It is well known in the art that rigid pipes, particularly those suffering from decay, can be lined with various plastics in order to restore the use of the pipe and/or to achieve chemical or abrasion resistance.
As representative of the slip lining technique, reference is made to U.S. Pat. No. 4,496,499 issued on Jan. 29, 1985 which utilizes a non-collapsed plastic liner having an outside diameter sufficiently less than the inside diameter of the pipeline to enable drawing the liner through the pipeline section, but sufficiently large so that the liner can be non-destructively radially expanded against the inside wall of the pipeline. The non-collapsed liner is thereafter drawn into the pipe line section until the liner is substantially longitudinally co-extensive with the pipe line section followed by longitudinally stretching the liner within the section. After fixing the liner against longitudinal movement within the section, a bleeding port is opened in the section and the liner is thereafter radially expanded against the inside wall of the pipe line by a warm pressurized fluid to an extent to permanently change the liner's outside diameter from its original size to a size conforming to the inside diameter of the pipe line while bleeding through the bleeding port.
This prior art technique however has several disadvantages. One such disadvantage is the shipping costs involved in transporting the non-collapsed liner. Another disadvantage is the excessive time and criticality of the installation procedure.
In order to eliminate some of the disadvantages the art has resorted to preparation of collapsed liners which can be shipped at much lower costs. The collapsed or deformed liner arrives at the site and is inserted into the decayed pipe in deformed condition. This makes insertion much easier with the collapsed liner. After insertion the liner ends are then capped and inflated to their original configuration by the action of pressurized steam and/or hot water.
The present invention is concerned with an apparatus for deforming pipe liners.
Accordingly it is the object of the present invention to provide an apparatus for deforming pipe liners into shapes which permit easy shipment of the pipe liner and which permits easy insertion of the pipe liner into the pipe to be lined.
Another object of the invention is to provide an apparatus for deforming pipe liners which apparatus is capable of deforming pipe liners in various configurations.
Another object of the invention is to provide a collapsed plastic liner which can be radially expanded in the pipe to be lined with hot pressurized fluids.
These and other objects will become apparent from the description of the invention which follows.